Premature ventricular contraction
PVC.
A contraction of the lower chambers of the heart, the ventricles, which occur earlier than usual, because of abnormal electrical activity of the ventricles.
The premature contraction is followed by a pause, as the heart electrical system 'resets' itself and the contraction following the pause is usually more forceful than normal.
These more forceful contractions are frequently perceived as palpitations.
Also called an extrasystole